A Genetic Framework for the Control of Cell Division and Differentiation in the Root Meristem
A Genetic Framework for the Control of Cell Division and Differentiation in the Root Meristem
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DOI：
10.1126/science.1164147
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发表时间：
2008-11-28
期刊：
影响因子：
56.9
通讯作者：
Sabatini, Sabrina
中科院分区：
文献类型：
--
作者：
Dello Ioio, Raffaele;Nakamura, Kinu;Sabatini, Sabrina
植物的生长和发育是由分生组织维持的。分生组织的活动由生长素和细胞分裂素控制，这两种激素在决定特定发育产量方面的相互作用仍然知之甚少。通过对拟南芥的遗传和分子综合分析，我们发现一个主要的细胞分裂素反应转录因子ARR1激活了生长素信号转导抑制基因SHY2/IAA3(SHY2)，该基因负调控PIN生长素运输促进基因：因此，细胞分裂素引起生长素的再分配，促进细胞分化。相反，生长素介导SHY2蛋白的降解，维持PIN活性和细胞分裂。因此，控制根分生组织大小和根生长所需的细胞分化和分裂平衡是细胞分裂素和生长素通过一个简单的调节电路汇聚到SHY2基因上相互作用的结果。
Plant growth and development are sustained by meristems. Meristem activity is controlled by auxin and cytokinin, two hormones whose interactions in determining a specific developmental output are still poorly understood. By means of a comprehensive genetic and molecular analysis in Arabidopsis, we show that a primary cytokinin- response transcription factor, ARR1, activates the gene SHY2/IAA3 (SHY2), a repressor of auxin signaling that negatively regulates the PIN auxin transport facilitator genes: thereby, cytokinin causes auxin redistribution, prompting cell differentiation. Conversely, auxin mediates degradation of the SHY2 protein, sustaining PIN activities and cell division. Thus, the cell differentiation and division balance necessary for controlling root meristem size and root growth is the result of the interaction between cytokinin and auxin through a simple regulatory circuit converging on the SHY2 gene.